Europa Archives

May 11, 2017May 13, 2017 by Matt Williams

Europa Lander Could Carry a Microphone and “Listen” to the Ice to Find Out What’s Underneath

Artist's rendering of a possible Europa Lander mission, which would explore the surface of the icy moon in the coming decades. Credit:: NASA/JPL-Caltech

Between the Europa Clipper and the proposed Europa Lander, NASA has made it clear that it intends to send a mission to this icy moon of Jupiter in the coming decade. Ever since the Voyager 1 and 2 probes conducted their historic flybys of the moon in 1973 and 1974 – which offered the first indications of a warm-water ocean in the moon’s interior – scientists have been eager to peak beneath the surface and see what is there.

Towards this end, NASA has issued a grant to a team of researchers from Arizona State University to build and test a specially-designed seismometer that the lander would use to listen to Europa’s interior. Known as the Seismometer for Exploring the Subsurface of Europa (SESE), this device will help scientists determine if the interior of Europa is conducive to life.

According to the profile for the Europa Lander, this microphone would be mounted to the robotic probe. Once it reached the surface of the moon, the seismometer would begin collecting information on Europa’s subsurface environment. This would include data on its natural tides and movements within the shell, which would determine the icy surface’s thickness.

*Image of Europa’s ice shell, taken by the Galileo spacecraft, of fractured “chaos terrain”. Credit: NASA/JPL-Caltech*

It would also determine if the surface has pockets of water – i.e. subsurface lakes – and see how often water rises to the surface. For some time, scientists have suspected that Europa’s “chaos terrain” would be the ideal place to search for evidence of life. These features, which are basically a jumbled mess of ridges, cracks, and plains, are believed to be spots where the subsurface ocean is interacting with the icy crust.

As such, any evidence of organic molecules or biological organisms would be easiest to find there. In addition, astronomers have also detected water plumes coming from Europa’s surface. These are also considered to be one of the best bets for finding evidence of life in the interior. But before they can be explored directly, determining where reservoirs of water reside beneath the ice and if they are connected to the interior ocean is paramount.

And this is where instruments like the SESE would come into play. Hongyu Yu is an exploration system engineer from ASU’s School of Earth and Space Exploration and the leader of the SESE team. As he stated in a recent article by ASU Now, “We want to hear what Europa has to tell us. And that means putting a sensitive ‘ear’ on Europa’s surface.”

While the idea of a Europa Lander is still in the concept-development stage, NASA is working to develop all the necessary components for such a mission. As such, they have provided the ASU team with a grant to develop and test their miniature seismometer, which measures no more than 10 cm (4 inches) on a side and could easily be fitted aboard a robotic lander.

*Europa’s “Great Lake.” Scientists speculate many more exist throughout the shallow regions of the moon’s icy shell. Credit: Britney Schmidt/Dead Pixel FX/Univ. of Texas at Austin.*

More importantly, their seismometer differs from conventional designs in that it does not rely on a mass-and-spring sensor. Such a design would be ill-suited for a mission to another body in our Solar System since it needs to be positioned upright, which requires that it be carefully planted and not disturbed. What’s more, the sensor needs to be placed within a complete vacuum to ensure accurate measurements.

By using a micro-electrical system with a liquid electrolyte for a sensor, Yu and his team have created a seismometer that can operate under a wider range of conditions. “Our design avoids all these problems,” he said. “This design has a high sensitivity to a wide range of vibrations, and it can operate at any angle to the surface. And if necessary, they can hit the ground hard on landing.”

As Lenore Dai – a chemical engineer and the director of the ASU’s School for Engineering of Matter, Transport and Energy – explained, the design also makes the SESE well suited for exploring extreme environments – like Europa’s icy surface. “We’re excited at the opportunity to develop electrolytes and polymers beyond their traditional temperature limits,” she said. “This project also exemplifies collaboration across disciplines.”

The SESE can also take a beating without compromising its sensor readings, which was tested when the team struck it with a sledgehammer and found that it still worked afterwards. According to seismologist Edward Garnero, who is also a member of the SESE team, this will come in handy. Landers typically have six to eight legs, he claims, which could be mated with seismometers to turn them into scientific instruments.

*Artist’s concept of chloride salts bubbling up from Europa’s liquid ocean and reaching the frozen surface. Credit: NASA/JPL-Caltech*

Having this many sensors on the lander would give scientists the ability to combine data, allowing them to overcome the issue of variable seismic vibrations recorded by each. As such, ensuring that they are rugged is a must.

“Seismometers need to connect with the solid ground to operate most effectively. If each leg carries a seismometer, these could be pushed into the surface on landing, making good contact with the ground. We can also sort out high frequency signals from longer wavelength ones. For example, small meteorites hitting the surface not too far away would produce high frequency waves, and tides of gravitational tugs from Jupiter and Europa’s neighbor moons would make long, slow waves.”

Such a device could also prove crucial to missions other “ocean worlds” within the Solar System, which include Ceres, Ganymede, Callisto, Enceladus, Titan and others. On these bodies as well, it is believed that life could very well exist in warm-water oceans that lie beneath the surface. As such, a compact, rugged seismometer that is capable of working in extreme-temperature environments would be ideal for studying their interiors.

What’s more, missions of this kind would be able to reveal where the ice sheets on these bodies are thinnest, and hence where the interior oceans are most accessible. Once that’s done, NASA and other space agencies will know exactly where to send in the probe (or possibly the robotic submarine). Though we might have to wait a few decades on that one!

Further Reading: ASU Now

February 10, 2017February 11, 2017 by Bob King

This Is The Highest Resolution Image Of Europa We Have … For Now

This is the highest resolution image taken by Galileo at Europa — Jupiter’s 4th largest moon — until our next mission to the planet. It was obtained at an original image scale of 19 feet (6 meters) per pixel. The gray line down the middle resulted from missing data that was not transmitted by Galileo. Credit: NASA/JPL-Caltech

In the movie 2010: The Year We Make Contact, the sequel to Stanley’s Kubrick’s 2001: A Space Odyssey, black Monoliths multiply, converge and transform Jupiter into a new star. We next hear astronaut David Bowman’s disembodied voice with this message: “All these worlds are yours except Europa. Attempt no landing there.” The newborn sun warms Europa, transforming the icy landscape into a primeval jungle. At the end, a single Monolith appears in the swamp, waiting once again to direct the evolution of intelligent life forms.

Stay away from Europa? No way. It’s just too fascinating a place with its jigsaw-puzzle ice sheets, crisscross valleys, miles of ice on top and a warm, salty ocean below. The movie was prescient — if you’re going to search for life elsewhere in the solar system, Europa’s one of the best candidates.

While we’ve sent spacecraft to photograph and study the icy moon during orbital flybys, no lander has yet to touch the surface. That may change soon. In early 2016, in response to a congressional directive, NASA’s Planetary Science Division began a pre-Phase A study to assess the science value and engineering design of a future Europa lander mission. In June 2016, NASA convened a 21-member team of scientists for the Science Definition Team (SDT). The team put together set of science objectives and measurements for the mission concept and submitted the report to NASA on Feb. 7.

This artist’s rendering illustrates a conceptual design for a potential future mission to land a robotic probe on the surface of Jupiter’s moon Europa. The lander is shown with a sampling arm extended, having previously excavated a small area on the surface. The circular dish on top is a combo high-gain antenna and camera mast, with stereo imaging cameras mounted on the back of the antenna. Three vertical shapes located around the top center of the lander are attachment points for cables that would lower the rover from a sky crane, the planned landing system for this mission concept. Credits: NASA/JPL-Caltech

The report lists three science goals for the mission. The primary goal is to search for evidence of life on Europa. The other goals are to determine the habitability of Europa by directly analyzing material from the surface, and to characterize the surface and subsurface to support future robotic exploration of Europa and its ocean.

This image from NASA’s Galileo spacecraft show the intricate detail of Europa’s icy surface. The red staining occurs in areas where briny waters from below — possibly mixed with sulfur — reach the surface. Radiation from Jupiter bombards the material, causing it to redden. Gravitational flexing of the moon as it orbits Jupiter fractures the icy crust into a chaotic landscape of snaking valleys and ice sheets. It also warms the ocean beneath the crust, potentially making it habitable. Credit: NASA/JPL-Caltech

The evidence is quite strong that Europa, with a diameter of 1,945 miles — slightly smaller than Earth’s moon — has a global saltwater ocean beneath its icy crust. This ocean has at least twice as much water as Earth’s oceans. Two things make Europa’s ocean unique and give the moon a greater chance of supporting microbial life compared to say, Ganymede and Enceladus, which also hold water reservoirs beneath their crusts.

Astronomers hypothesize that chloride salts bubble up from the icy moon’s global liquid ocean and reach the frozen surface where they are bombarded with sulfur from volcanoes on Jupiter’s innermost large moon Io. Molecular signs of life may be transported where they could be detected by a spacecraft. In this illustration, we see Europa (foreground), Jupiter (right) and Io (middle). Credit: NASA/JPL-Caltech

One: the ocean is relatively close to the surface, just 10-15 miles below the moon’s icy shell. Radiation from Jupiter (high-speed electrons and protons) bombards ice, sulfur and salts on the surface to create compounds that could trickle down into warmer regions and used by living things for growth and metabolism.

Broken plates and blocks of water ice now frozen in place in Europa’s crust suggest they floated freely for a time. Credit: NASA/JPL-Caltech

Two: While recent discoveries have shown that many bodies in the solar system either have subsurface oceans now, or may have in the past, Europa is one of only two places where the ocean appears to be in contact with a rocky seafloor (the other being Saturn’s moon Enceladus). This rare circumstance makes Europa one of the highest priority targets in the search for present-day life beyond Earth.

On Earth, chemical interactions between life and lifeless rock in deep oceans and within the outer crust provide the energy needed to power and sustain microbial life. For all we know, deep sea volcanoes belch essential elements into the salty waters spawned by the constant flexing and heating of the moon as it orbits Jupiter every 85 hours.

This mosaic of images includes the most detailed view of the surface of Jupiter’s moon Europa obtained by NASA’s Galileo mission. This observation was taken with the sun relatively high in the sky, so most of the brightness variations are due to color differences in the surface material rather than shadows. Ridge tops, brightened by frost, contrast with darker valleys, perhaps due to small temperature variations allow frost to accumulate in slightly colder, higher-elevation locations. Credit: NASA/JPL-Caltech

The SDT was tasked with developing a life-detection strategy, a first for a NASA mission since the Mars Viking mission era more than four decades ago. The report makes recommendations on the number and type of science instruments that would be required to confirm if signs of life are present in samples collected from the icy moon’s surface.

The team also worked closely with engineers to design a system capable of landing on a surface about which very little is known. Given that Europa has no atmosphere, the team developed a concept that could deliver its science payload to the icy surface without the benefit of technologies like a heat shield or parachutes.

This artist’s rendering shows NASA’s Europa mission spacecraft, which is being developed for a launch sometime in the 2020s. The spacecraft would orbit around Jupiter in order to perform a detailed investigation of Europa before a follow-up landing mission. The probe could look for “biosignatures” or molecular signs of life, such as the byproducts of metabolism, transported from the moon’s ocean to its surface. Credit: NASA/JPL-Caltech

The concept lander is separate from the solar-powered Europa multiple flyby mission, now in development for launch in the early 2020s. The spacecraft will arrive at Jupiter after a multi-year journey, orbiting the gas giant every two weeks for a series of 45 close flybys of Europa. The multiple flyby mission will investigate Europa’s habitability by mapping its composition, determining the characteristics of the ocean and ice shell, and increasing our understanding of its geology. The mission also will lay the foundation for a future landing by performing detailed reconnaissance using its powerful cameras.

We can’t help but be excited by the prospects of life-seeking missions to Europa. Sometimes wonderful things come in small packages.

September 26, 2016October 5, 2016 by Matt Williams

Europa’s Venting Global Ocean May Be Easier To Reach Than We Thought

Artist's impression of a water vapor plume on Europa. Credit: NASA/ESA/K. Retherford/SWRI

Last week, on Tuesday, September 20th, NASA announced that they had made some interesting findings about Jupiter’s icy moon Europa. These were based on images taken by the Hubble Space Telescope, the details of which would be released on the following week. Needless to say, since then, the scientific community and general public have been waiting with baited breath.

Earlier today (September 26th) NASA put an end to the waiting and announced the Hubble findings during a NASA Live conference. According to the NASA panel, which was made up of members of the research team, this latest Europa-observing mission revealed evidence of plumes of saline water emanating from Europa’s surface. If true, this would mean that the moon’s subsurface ocean would be more accessible than previously thought.

Using Hubble’s Space Telescope Imaging Spectrograph (STIS) instrument, the team conducted observations of Jupiter and Europa in the ultra-violet spectrum over the course of 15 months. During that time, Europa passed in front of Jupiter (occulted the gas giant) on 10 separate occasions.

And on three of these occasions, the team saw what appeared to be plumes of water erupting from the surface. These plumes were estimated to be reaching up to 200 km (125 miles) from the southern region of Europa before (presumably) raining back onto the surface, depositing water ice and material from the interior.

The purpose of the observation was to examine Europa’s possible extended atmosphere (aka. exosphere). The method the team employed was similar to the one used to detect atmospheres around extra-solar planets. As William Sparks of the Space Telescope Science Institute (STScI) in Baltimore (and the team leader), explained in a NASA press release:

“The atmosphere of an extrasolar planet blocks some of the starlight that is behind it. If there is a thin atmosphere around Europa, it has the potential to block some of the light of Jupiter, and we could see it as a silhouette. And so we were looking for absorption features around the limb of Europa as it transited the smooth face of Jupiter.”

When they looked at Europa using this same technique, they noted that small patches on the surface were dark, indicating the absorption of UV light. This corresponded to previous work done by Lorenz Roth (of the Southwest Research Institute) and his team of researchers in 2012. At this time, they detected evidence of water vapor coming from Europa’s southern polar region.

Europa transit illustration. Europa orbits Jupiter every 3 and a half days, and on every orbit it passes in front of Jupiter, raising the possibility of plumes being seen as silhouettes absorbing the background light of Jupiter. Credits: A. Field (STScI)

As they indicated in a paper detailing their results – titled “Transient Water Vapor at Europa’s South Pole” – Roth’s team also relied on UV observations made using the Hubble telescope. Noting a statistically coincident amount of hydrogen and oxygen emissions, they concluded that this was the result of ejected water vapor being broken apart by Jupiter’s radiation (a process known as radiolysis).

Though their methods differed, Sparks and his research team also found evidence of these apparent water plumes, and in the same place no less. Based on the latest information from STIS, most of the apparent plumes are located in the moon’s southern polar region while another appears to be located in the equatorial region.

“When we calculate in a completely different way the amount of material that would be needed to create these absorption features, it’s pretty similar to what Roth and his team found,” Sparks said. “The estimates for the mass are similar, the estimates for the height of the plumes are similar. The latitude of two of the plume candidates we see corresponds to their earlier work.”

Another interesting conclusion to come from this and the 2012 study is the likelihood that these water plumes are intermittent. Basically, Europa is tidally-locked world, which means the same side is always being presented to us when it transits Jupiter. This occus once every 3.5 days, thus giving astronomers and planetary scientists plenty of viewing opportunities.

This composite image shows suspected plumes of water vapor erupting at the 7 o’clock position off the limb of Jupiter’s moon Europa. The Hubble data were taken on January 26, 2014. Credit: Credits: NASA/ESA/W. Sparks (STScI)/USGS Astrogeology Science Center

But the fact that plumes have been observed at some points and not others would seem to indicate that they are periodic. In addition, Roth’s team attempted to spot one of the plume’s observed by Sparks and his colleagues a week after they reported it. However, they were unable to locate this supposed water source. As such, it would appear that the plumes, if they do exist, are short-lived.

These findings are immensely significant for two reasons. On the one hand, they are further evidence that a warm-water, saline ocean exists beneath Europa’s icy surface. On the other, they indicate that any future mission to Europa would be able to access this salt-water ocean with greater ease.

Ever since the Galileo spacecraft conducted a flyby of the Jovian moon, scientists have believed that an interior ocean is lying beneath Europa’s icy surface – one that has between two and three times as much water as all of Earth’s oceans combined. However, estimates of the ice’s thickness range from it being between 10 to 30 km (6–19 mi) thick – with a ductile “warm ice” layer that increases its total thickness to as much as 100 km (60 mi).

Knowing the water periodically reaches the surface through fissures in the ice would mean that any future mission (which would likely include a submarine) would not have to drill so deep. And considering that Europa’s interior ocean is considered to be one of our best bets for finding extra-terrestrial life, knowing that the ocean is accessible is certainly exciting news.

A comparison of 2014 transit and 2012 Europa aurora observations. The raw transit image, left, has dark fingers or patches of possible absorption in the same place that a different team (led by Lorenz Roth) found auroral emission from hydrogen and oxygen, the dissociation products of water. Credits: NASA, ESA, W. Sparks (left image) L. Roth (right image) — *A comparison of 2014 transit and 2012 Europa aurora observations. Credits: NASA, ESA, W. Sparks (left image) L. Roth (right image)*

And the news is certainly causing its fair share of excitement for the people who are currently developing NASA’s proposed Mission to Europa, which is scheduled to launch sometime in the 2020s. As Dr. Cynthia B. Phillips, a Staff Scientist and the Science Communications Lead for the Europa Project, told Universe Today via email:

“This new discovery, using Hubble Space Telescope data, is an intriguing data point that helps lend support to the idea that there are active plumes on Europa today. While not an absolute confirmation, the new Sparks et al. result, in combination with previous observations by Roth et al. (also using HST but with a different technique), is consistent with the presence of intermittent plumes ejecting water vapor from the Southern Hemisphere of Europa. Such observations are difficult to perform from Earth, however, even with Hubble, and thus these results remain inconclusive.

“Confirming the presence or absence of plumes on Europa, as well as investigating many other mysteries of this icy ocean world, will require a dedicated spacecraft in the Jupiter system. NASA currently plans to send a multiple-flyby spacecraft to Europa, which would make many close passes by Europa in the next decade. The spacecraft’s powerful suite of scientific instruments will be able to study Europa’s surface and subsurface in unprecedented detail, and if plumes do exist, it will be able to observe them directly and even potentially measure their composition. Until the Europa spacecraft is in place, however, Earth-based observations such as the new Hubble Space Telescope results will remain our best technique to observe Jupiter’s mysterious moon.”

Naturally, Sparks was clear that this latest information was not entirely conclusive. While he believes that the results were statistically significant, and that there were no indications of artifacts in the data, he also emphasized that observations conducted in the UV wavelength are tricky. Therefore, more evidence is needed before anything can be said definitively.

In the future, it is hoped that future observation will help to confirm the existence of water plumes, and how these could have helped create Europa’s “chaos terrain”. Future missions, like NASA’s James Webb Space Telescope (scheduled to launch in 2018) could help confirm plume activity by observing the moon in infrared wavelengths.

As Paul Hertz, the director of the Astrophysics Division at NASA Headquarters in Washington, said:

“Hubble’s unique capabilities enabled it to capture these plumes, once again demonstrating Hubble’s ability to make observations it was never designed to make. This observation opens up a world of possibilities, and we look forward to future missions — such as the James Webb Space Telescope — to follow up on this exciting discovery.”

Other team members include Britney Schmidt, an assistant professor at the School of Earth and Atmospheric Sciences at Georgia Institute of Technology in Atlanta; and Jennifer Wiseman, senior Hubble project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Their work will be published in the Sept. 29 issue of the Astrophysical Journal.

And be sure to enjoy this video by NASA about this exciting find:

Further Reading: NASA Live

September 21, 2016October 5, 2016 by Evan Gough

Hubble’s Surprising Find On Europa To Be Announced By NASA Monday

Europa as imaged by the Galileo spacecraft. Europa is a prime target in the search for life because of its sub-surface ocean. Image: NASA/JPL-Caltech/SETI Institute

NASA will make a “surprising” announcement about Jupiter’s moon Europa on Monday, Sept. 26th, at 2:00 PM EDT. They haven’t said much, other than there is “surprising evidence of activity that may be related to the presence of a subsurface ocean on Europa.” Europa is a prime target for the search for life because of its subsurface ocean.

The new evidence is from a “unique Europa observing campaign” aimed at the icy moon. The Hubble Space Telescope captured the images in these new findings, so maybe we’ll be treated to some more of the beautiful images that we’re accustomed to seeing from the Hubble.

Images from NASA's Galileo spacecraft show the intricate detail of Europa's icy surface. Image: NASA/JPL-Caltech/ SETI Institute — Images from NASA’s Galileo spacecraft show the intricate detail of Europa’s icy surface. Image: NASA/JPL-Caltech/ SETI Institute

We always welcome beautiful images, of course. But the real interest in Europa lies in its suitability for harboring life. Europa has a frozen surface, but underneath that ice there is probably an ocean. The frozen surface is thought to be about 10 – 30 km thick, and the ocean may be about 100 km (62 miles) thick. That’s a lot of water, perhaps double what Earth has, and that water is probably salty.

Back in 2012, the Hubble captured evidence of plumes of water vapor escaping from Europa’s south pole. Hubble didn’t directly image the water vapor, but it “spectroscopically detected auroral emissions from oxygen and hydrogen” according to a NASA news release at the time.

This artist's illustration shows what plumes of water vapour might look like being ejected from Europa's south pole. Image: NASA, ESA, L. Roth (Southwest Research Institute, USA/University of Cologne, Germany) and M. Kornmesser. — This artist’s illustration shows what plumes of water vapour might look like being ejected from Europa’s south pole. Image: NASA, ESA, L. Roth (Southwest Research Institute, USA/University of Cologne, Germany) and M. Kornmesser.

There are other lines of evidence that support the existence of a sub-surface ocean on Europa. But there are a lot of questions. Will the frozen top layer be several tens of kilometres thick, or only a few hundred meters thick? Will the sub-surface ocean be warm, liquid water? Or will it be frozen too, but warmer than the surface ice and still convective?

Two models of the interior of Europa. Image: NASA/JPL.

Hopefully, new evidence from the Hubble will answer these questions definitively. Stay tuned to Monday’s teleconference to find out what NASA has to tell us.

These are the scientists who will be involved in the teleconference:

Paul Hertz, director of the Astrophysics Division at NASA Headquarters in Washington
William Sparks, astronomer with the Space Telescope Science Institute in Baltimore
Britney Schmidt, assistant professor at the School of Earth and Atmospheric Sciences at Georgia Institute of Technology in Atlanta
Jennifer Wiseman, senior Hubble project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland

The NASA website will stream audio from the teleconference.

More About Europa:

August 19, 2016September 26, 2016 by Evan Gough

Europa Clipper Team Braces For Bad News

An artist's concept of the Europa mission. The multi-year mission would conduct fly-bys of Europa designed to protect it from the extreme environment there. Image: NASA/JPL-Caltech

Jupiter’s moon Europa is a juicy target for exploration. Beneath its surface of ice there’s a warm salty, ocean. Or potentially, at least. And if Earth is our guide, wherever you find a warm, salty, ocean, you find life. But finding it requires a dedicated, and unique, mission.

If each of the bodies in our Solar System weren’t so different from each other, we could just have one or two types of missions. Things would be much easier, but also much more boring. But Europa isn’t boring, and it won’t be easy to explore. Exploring it will require a complex, custom mission. That means expensive.

NASA’s proposed mission to Europa is called the Europa Clipper. It’s been in the works for a few years now. But as the mission takes shape, and as the science gets worked out, a parallel process of budget wrangling is also ongoing. And as reported by SpaceNews.com there could be bad news incoming for the first-ever mission to Europa.

At issue is next year’s funding for the Europa Clipper. Officials with NASA’s Outer Planets Assessment Group are looking for ways to economize and cut costs for Fiscal Year (FY) 2017, while still staying on track for a mission launch in 2022.

According to Bob Pappalardo, Europa Clipper’s project scientist at the Jet Propulsion Laboratory, funding will be squeezed in 2017. “There is this squeeze in FY17 that we have,” said Pappalardo. “We’re asking the instrument teams and various other aspects of the project, given that squeeze, what will it take in the out years to maintain that ’22 launch.”

As for the actual dollar amounts, there are different numbers floating around, and they don’t all jive with each other. In 2016, the Europa Mission received $175 million from Congress, but in the administration’s budget proposal for 2017, they only requested $49.6 million.

There’s clearly some uncertainty in these numbers, and that uncertainty is reflected in Congress, too. An FY 2017 House bill earmarks $260 million for the Europa mission. And the Senate has crafted a bill in support of the mission, but doesn’t allocate any funding for it. Neither the Senate nor the Congress has passed their bills.

This is not the first time that a mis-alignment has appeared between NASA and the different levels of government when it comes to funding. It’s pretty common. It’s also pretty common for the higher level of funding to prevail. But it’s odd that NASA’s requested amount is so low. NASA’s own low figure of $49.6 million is fuelling the perception that they themselves are losing interest in the Europa Clipper.

But SpaceNews.com is reporting that that is not the case. According to Curt Niebur, NASA’s program scientist for the Europa mission, “Everyone is aware of how supportive and generous Congress has been of this mission, and I’m happy to say that that support and encouragement is now shared by the administration, and by NASA as well. Everybody is on board the Europa Clipper and getting this mission to the launch pad as soon as our technical challenges and our budget will allow.”

What all this seems to mean is that the initial science and instrumentation for the mission will be maintained, but no additional capacity will be added. NASA is no longer considering things like free-flying probes to measure the plumes of water ice coming off the moon. According to Niebur, “The additional science value provided by these additions was not commensurate with the associated impact to resources, to accommodation, to cost. There just wasn’t enough science there to balance that out.”

The Europa Clipper will be a direct shot to Europa, without any gravity assist on the way. It will likely be powered by the Space Launch System. The main goal of the mission is to learn more about the icy moon’s potential habitability. There are tantalizing clues that it has an ocean about 100 km thick, kept warm by the gravity-tidal interactions with Jupiter, and possibly by radioactive decay in the rocky mantle. There’s also some evidence that the composition of the sub-surface ocean is similar to Earth’s.

Mars is a fascinating target, no doubt about it. But as far as harbouring life, Europa might be a better bet. Europa’s warm, salty ocean versus Mar’s dry, cold surface? A lot of resources have been spent studying Mars, and the Europa mission represents a shift in resources in that regard.

It’s unfortunate that a few tens of million dollars here or there can hamper our search for life beyond Earth. But the USA is a democracy, so that’s the way it is. These discrepancies and possible disputes between NASA and the different levels of government may seem disconcerting, but that’s the way these things get done.

At least we hope it is.

Sources: SpaceNews.com

Europa on Universe Today:

SpaceNews.com

April 15, 2016April 15, 2016 by Jason Major

Icy Hot: Europa’s Frozen Crust Could Be Warmer Than We Thought

NASA is looking for a new Planetary Protection Officer to protect Earth and the other bodies of the Solar System from harmful contamination. Credit: NASA/JPL-Caltech/SETI Institute.

All the worlds may be ours except Europa but that only makes the ice-covered moon of Jupiter all the more intriguing. Beneath Europa’s thin crust of ice lies a tantalizing global ocean of liquid water somewhere in the neighborhood of 100 kilometers deep—which adds up to more liquid water than is on the entire surface of the Earth. Liquid water plus a heat source(s) to keep it liquid plus the organic compounds necessary for life and…well, you know where the thought process naturally goes from there.

And now it turns out Europa may have even more of a heat source than we thought. Yes, a big component of Europa’s water-liquefying warmth comes from tidal stresses enacted by the massive gravity of Jupiter as well as from the other large Galilean moons. But exactly how much heat is created within the moon’s icy crust as it flexes has so far only been loosely estimated. Now, researchers from Brown University in Providence, RI and Columbia University in New York City have modeled how friction creates heat within ice under stress, and the results were surprising.

Continue reading “Icy Hot: Europa’s Frozen Crust Could Be Warmer Than We Thought”

February 12, 2016February 13, 2016 by Ken Kremer

Obama Administration Proposes Smaller 2017 NASA Budget of $19 Billion with Big Exploration Cuts

NASA releases budget request for Fiscal Year 2017. Credit: NASA

The Obama Administration has announced its new Federal budget and is proposing to cut NASA’s Fiscal Year 2017 Budget to $19 billion by carving away significant funding for deep space exploration, whereas the overall US Federal budget actually increases to over $4.1 trillion.

This 2017 budget request amounts to almost $300 million less than the recently enacted NASA budget for 2016 and specifically stipulates deep funding cuts for deep space exploration programs involving both humans and robots, during President Obama’s final year in office.

The 2017 budget proposal would slash funding to the very programs designed to expand the frontiers of human knowledge and aimed at propelling humans outward to the Red Planet and robots to a Jovian moon that might be conducive to the formation of life.

Absent sufficient and reliable funding to keep NASA’s exploration endeavors on track, further launch delays are almost certainly inevitable – thereby fraying American leadership in space and science.

The administration is specifying big funding cuts to the ongoing development of NASA’s mammoth Space Launch System (SLS) heavy lift rocket and the state of the art Orion deep space crew capsule. They are the essential first ingredients to carry out NASA’s ambitious plans to send astronauts on deep space ‘Journey to Mars’ expeditions during the 2030s.

The overall Exploration Systems Development account for human deep space missions would be slashed about 18 percent from the 2016 funding level; from $4.0 Billion to only $3.3 Billion, or nearly $700 million.

SLS alone is reduced the most by $700 million from $2.0 billion to $1,31 billion, or a whopping 35 percent loss. Orion is reduced from $1.27 billion to $1.12 billion for a loss of some $150 million.

Make no mistake. These programs are already starved for funding and the Obama administration tried to force similar cuts to these programs in 2016, until Congress intervened.

Likewise, the Obama administration is proposing a draconian cut to the proposed robotic mission to Jupiter’s moon Europa that would surely delay the launch by at least another half a decade or more – to the late 2020s.

The Europa mission budget proposal is cut to only $49 million and the launch is postponed until the late 2020s. The mission received $175 million in funding in 2016 – amounting to a 72 percent reduction.

Furthermore there is no funding for a proposed lander and the launch vehicle changes from SLS to a far less powerful EELV – causing a year’s long increased travel time.

In order to maintain an SLS launch in approximately 2022, NASA would require a budget of about $150 million in 2017, said David Radzanowski, NASA’s chief financial officer, during a Feb. 9 teleconference with reporters.

Why is Europa worth exploring? Because Europa likely possesses a subsurface ocean of water and is a prime target in the search for life!

Overall, NASA’s hugely successful Planetary Sciences division suffers a huge and nearly 10 percent cut of $141 million to $1.51 billion – despite undeniably groundbreaking scientific successes this past year at Pluto, Ceres, Mars and more!

Altogether NASA would receive $19.025 billion in FY 2017. This totals $260 million less than the $19.285 billion appropriated in FY 2016, and thus corresponds to a reduction of 1.5 percent.

By contrast, the overall US Federal Budget will increase nearly 5 percent to approximately $4.1 trillion. Simple math demonstrates that NASA is clearly not a high priority for the administration. NASA’s share of the Federal budget comes in at less than half a cent on the dollar.

Orion crew module pressure vessel for NASA’s Exploration Mission-1 (EM-1) is unveiled for the first time on Feb. 3, 2016 after arrival at the agency’s Kennedy Space Center (KSC) in Florida. It is secured for processing in a test stand called the birdcage in the high bay inside the Neil Armstrong Operations and Checkout (O&C) Building at KSC. Launch to the Moon is slated in 2018 atop the SLS rocket. Credit: Ken Kremer/kenkremer.com

NASA’s Fiscal Year 2017 budget proposal was announced by NASA Administrator Charles Bolden during a televised ‘State of NASA’ address at the agency’s Langley Research Center in Virginia on Feb. 9.

Bolden did not dwell at all on the significant funding reductions for exploration.

“We are hitting our benchmarks with new exploration systems like the Space Launch System rocket and the Orion Crew Vehicle. A new consensus is emerging in the scientific and policy communities around our vision, timetable and plan for sending American astronauts to Mars in the 2030s.”

And he outlined some milestones ahead.

“We’ll continue to make great progress on the Space Launch System – SLS–rocket and we’re preparing for a second series of engine tests,” said Bolden.

“At the Kennedy Space Center, our teams will outfit Orion’s crew module with the spacecraft’s heat-shielding thermal protection systems, avionics and subsystems like electrical power storage, cabin pressure control and flight software –to name just a few.”

NASA’s Space Launch System (SLS) blasts off from launch pad 39B at the Kennedy Space Center in this artist rendering showing a view of the liftoff of the Block 1 70-metric-ton (77-ton) crew vehicle configuration. Credit: NASA/MSFC

NASA plans to launch the first combined SLS/Orion on the uncrewed Exploration Mission-1 (EM-1) in November 2018.

Indeed the Orion EM-1 pressure vessel just arrived at the Kennedy Space Center last week to completely install all the systems required for flight.

NASA’s Orion EM-1 crew module pressure vessel arrived at the Kennedy Space Center’s Shuttle Landing Facility tucked inside NASA’s Super Guppy aircraft on Feb 1, 2016. The Super Guppy opens its hinged nose to unload cargo. Credit: Ken Kremer/kenkremer.com

The launch date for the first crewed flight on EM-2 was targeted for 2021. But EM-2 is likely to slip to the right to 2023, due to insufficient funding.

Lack of funding will also force NASA to delay development of the far more capable and powerful Exploration Upper Stage (EUS) to propel Orion on deep space missions. It will now not be available for the SLS/EM-2 launch as hoped.

The proposed huge budget cuts to SLS, Orion and Europa are certain to arose the ire of multiple members of Congress and space interest groups, who just successfully fought to increase NASA’s FY 2016 budget for these same programs in the recently passed 2016 omnibus spending bill.

“This administration cannot continue to tout plans to send astronauts to Mars while strangling the programs that will take us there,” said Rep. Lamar Smith (R-Texas), Chairman of the House Science, Space, and Technology Committee, in a statement in response to the president’s budget proposal.

“President Obama’s FY17 budget proposal shrinks our deep space exploration programs by more than $800 million. And the administration once more proposes cuts of more than $100 million to the Planetary Science accounts, which have previously funded missions like this past year’s Pluto flyby.”

“This imbalanced proposal continues to tie our astronauts’ feet to the ground and makes a Mars mission all but impossible. This is not the proposal of an administration that is serious about maintaining America’s leadership in space.”

A "true color" image of the surface of Jupiter's moon Europa as seen by the Galileo spacecraft. Image credit: NASA/JPL-Caltech/SETI Institute — A “true color” image of the surface of Jupiter’s moon Europa as seen by the Galileo spacecraft. Image credit: NASA/JPL-Caltech/SETI Institute

“The Coalition for Deep Space Exploration … had hoped the request would reflect the priorities laid out for NASA in the FY16 Omnibus, for which there was broad support,” said Mary Lynne Dittmar, executive director of the Coalition for Deep Space Exploration, in a statement.

“Unfortunately this was not the case. The Coalition is disappointed with the proposed reduction in funding below the FY16 Omnibus for NASA’s exploration programs. We are deeply concerned about the Administration’s proposed cut to NASA’s human exploration development programs.”

“This proposed budget falls well short of the investment needed to support NASA’s exploration missions, and would have detrimental impacts on cornerstone, game-changing programs such as the super-heavy lift rocket, the Space Launch System (SLS), and the Orion spacecraft – the first spacecraft designed to reach multiple destinations in the human exploration of deep space.”

Homecoming view of NASA’s first Orion spacecraft after returning to NASA’s Kennedy Space Center in Florida on Dec. 19, 2014 after successful blastoff on Dec. 5, 2014. Credit: Ken Kremer - kenkremer.com — Homecoming view of NASA’s first Orion spacecraft after returning to NASA’s Kennedy Space Center in Florida on Dec. 19, 2014 after successful blastoff on Dec. 5, 2014. Credit: Ken Kremer – kenkremer.com

Funding for the James Webb Space Telescope (JWST) was maintained at planned levels to keep it on track for launch in 2018.

All 18 primary mirrors of NASA’s James Webb Space Telescope are seen fully installed on the backplane structure by technicians using a robotic arm (center) inside the massive clean room at NASA's Goddard Space Flight Center in Greenbelt, Maryland. Credit: Ken Kremer/kenkremer.com — All 18 primary mirrors of NASA’s James Webb Space Telescope are seen fully installed on the backplane structure by technicians using a robotic arm (center) inside the massive clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Credit: Ken Kremer/kenkremer.com

On Dec. 18, 2015, the US Congress passed and the president signed the 2016 omnibus spending bill which funds the US government through the remainder of the 2016 Fiscal Year.

As part of the omnibus bill, NASA’s approved budget amounted to nearly $19.3 Billion. That was an outstanding result and a remarkable turnaround to some long awaited good news from the decidedly negative outlook earlier in 2015.

The 2016 budget represented an increase of some $750 million above the Obama Administration’s proposed NASA budget allocation of $18.5 Billion for Fiscal Year 2016, and an increase of more than $1.2 Billion over the enacted budget for FY 2015.

Under the proposed NASA budget for Fiscal Year 2017, the fictional exploits of ‘The Martian’ will never become reality.

And the hunt for extraterrestrial life on the icy moons of the outer solar system is postponed yet again.

Scene from ‘The Martian’ starring Matt Damon as NASA astronaut Mark Watney contemplating magnificent panoramic vista while stranded alone on Mars. Credits: 20th Century Fox

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

This global mosaic view of Pluto was created from the latest high-resolution images to be downlinked from NASA’s New Horizons spacecraft and released on Sept. 11, 2015. The images were taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). This mosaic was stitched from over two dozen raw images captured by the LORRI imager and colorized. Right side mosaic comprises twelve highest resolution views of Tombaugh Regio heart shaped feature and shows objects as small as 0.5 miles (0.8 kilometers) in size. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/ Ken Kremer/kenkremer.com/Marco Di Lorenzo

June 18, 2015December 23, 2015 by Ken Kremer

NASA Gives ‘GO’ for Mission to Alien Ocean World at Jupiter Moon Europa

Artist's concept of NASA mission streaking over Europa. Credit: NASA/JPL

Artist’s concept of NASA mission streaking over ocean world of Europa. Credit: NASA/JPL
Story updated[/caption]

At long last NASA is heading back to Jupiter’s mysterious moon Europa and doing so in a big way – because scientists believe it harbors an alien ocean of water beneath an icy crust and therefore is “one of the most promising places in the solar system to search for signs of present-day life” beyond Earth.

Top NASA officials have now formally and officially green lighted the Europa ocean world robotic mission and given it the “GO” to move from early conceptual studies into development of the interplanetary spacecraft and mission hardware, to search for the chemical constituents of life.

“Today we’re taking an exciting step from concept to mission, in our quest to find signs of life beyond Earth,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington, in a NASA statement.

The goal is to investigate the habitability of Europa’s subsurface ocean, determine if it possesses the ingredients for life and advance our understanding of “Are we Alone?”

“Observations of Europa have provided us with tantalizing clues over the last two decades, and the time has come to seek answers to one of humanity’s most profound questions,” said Grunsfeld.

Water is a prerequisite for life as we know it.

“We know that on Earth everywhere there is water we find life,” says Robert Pappalardo, Europa mission project scientist.

“Therefore Europa is the most likely place to find life in our solar system today because we think there is a liquid water ocean beneath its surface.”

Video caption: Alien Ocean: NASA’s Mission to Europa. Could a liquid water ocean beneath the surface of Jupiter’s moon Europa have the ingredients to support life? Here’s how NASA’s mission to Europa would find out. Credit: NASA

After a thorough review of the mission concept, managers agreed that it “successfully completed its first major review by the agency and now is entering the development phase known as formulation

“It’s a great day for science,” said Joan Salute, Europa program executive at NASA Headquarters in Washington.

“We are thrilled to pass the first major milestone in the lifecycle of a mission that will ultimately inform us on the habitability of Europa.”

In a major milestone leading up to this mission development approval, NASA managers recently announced the selection of the nine science instruments that will fly on the agency’s long awaited planetary science mission to this intriguing world that many scientists suspect could support life, as I reported here last month.

“We are trying to answer big questions. Are we alone,” said Grunsfeld at the May 26 media briefing.

“The young surface seems to be in contact with an undersea ocean.”

This 12-frame mosaic provides the highest resolution view ever obtained of the side of Jupiter's moon Europa that faces the giant planet. It was obtained on Nov. 25, 1999 by the camera onboard the Galileo spacecraft, a past NASA mission to Jupiter and its moons. Credit: NASA/JPL/University of Arizona — This 12-frame mosaic provides the highest resolution view ever obtained of the side of Jupiter’s moon Europa that faces the giant planet. It was obtained on Nov. 25, 1999 by the camera onboard the Galileo spacecraft, a past NASA mission to Jupiter and its moons. Credit: NASA/JPL/University of Arizona

Planetary scientists have long desired a speedy to return on Europa, ever since the groundbreaking discoveries of NASA’s Galileo Jupiter orbiter in the 1990s showed that the alien world possessed a substantial and deep subsurface ocean beneath an icy shell that appears to interact with and alter the moon’s surface in recent times.

NASA’s Europa mission would blastoff perhaps as soon as 2022, depending on the budget allocation and rocket selection – whose candidates include the heavy lift Space Launch System (SLS) now under development to launch astronauts on deep space expedition to the Moon, Asteroids and Mars.

The solar powered Europa probe will go into orbit around Jupiter for a three year mission in order to minimize exposure to the intense radiation region that could harm the spacecraft.

The Europa mission goal is to investigate whether the tantalizing icy Jovian moon, similar in size to Earth’s moon, could harbor conditions suitable for the evolution and sustainability of life in the suspected ocean.

It will be equipped with high resolution cameras, spectrometers and radar, several generations beyond anything before to map the surface in unprecedented detail and determine the moon’s composition and subsurface character. And it will search for subsurface lakes and seek to sample erupting vapor plumes like those occurring today on Saturn’s tiny moon Enceladus.

There will many opportunities for close flybys of Europa during the three year primary mission to conduct unprecedented studies of the composition and structure of the surface, icy shell and oceanic interior.

“During the three year mission, the orbiter will conduct 45 close flyby’s of Europa,” Curt Niebur, Europa program scientist at NASA Headquarters in Washington, told Universe Today.

“These will occur about every two to three weeks.”

The close flyby’s will vary in altitude from 16 miles to 1,700 miles (25 kilometers to 2,700 kilometers).

Europa rising. The icy moon hangs above Jupiter cloud tops in a @NASANewHorizons image from 2007. Credit: NASA

The mission currently has a budget of about $10 million for 2015 and $30 Million in 2016. Over the next three years the mission concept will be further defined.

The mission will be managed by NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California and is expected to cost in the range of at least $2 Billion or more.

The nine science instruments are described in my earlier story- here. They will be developed and built by Johns Hopkins University Applied Physics Laboratory (APL); JPL; Arizona State University, Tempe; the University of Texas at Austin; Southwest Research Institute, San Antonio and the University of Colorado, Boulder.

This artist's rendering shows a concept for a future NASA mission to Europa in which a spacecraft would make multiple close flybys of the icy Jovian moon, thought to contain a global subsurface ocean. Credits: NASA/JPL-Caltech — This artist’s rendering shows a concept for a future NASA mission to Europa in which a spacecraft would make multiple close flybys of the icy Jovian moon, thought to contain a global subsurface ocean. Credits: NASA/JPL-Caltech

Right now there is another NASA probe bound for Jupiter, the solar powered Juno orbiter that will investigate the origin of the gas giant. But Juno will not be conducting any observations or flyby’s of Europa.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

………….

Learn more about SpaceX, Europa, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events:

Jun 25-27: “SpaceX launch, Orion, Commercial crew, Curiosity explores Mars, MMS, Antares and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

May 26, 2015December 23, 2015 by Ken Kremer

NASA Selects Mission Science Instruments Searching for Habitability of Jupiter’s Ocean Moon Europa

The fascinating surface of Jupiter’s icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA's Galileo spacecraft in the late 1990s. This is the color view of Europa from Galileo that shows the largest portion of the moon's surface at the highest resolution. Credits: NASA/JPL-Caltech/SETI Institute

In a major move forward on a long dreamed of mission to investigate the habitability of the subsurface ocean of Jupiter’s mysterious moon Europa, top NASA officials announced today, Tuesday, May 26, the selection of nine science instruments that will fly on the agency’s long awaited planetary science mission to an intriguing world that many scientists suspect could support life.

“We are on our way to Europa,” proclaimed John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington, at a media briefing today outlining NASA’s plans for a mission dedicated to launching in the early to mid-2020s. “It’s a mission to inspire.”

“We are trying to answer big questions. Are we alone?”

“The young surface seems to be in contact with an undersea ocean.”

It will be equipped with high resolution cameras, radar and spectrometers, several generations beyond anything before to map the surface in unprecedented detail and determine the moon’s composition and subsurface character. And it will search for subsurface lakes and seek to sample erupting vapor plumes like those occurring today on Saturn’s tiny moon Enceladus.

“Europa has tantalized us with its enigmatic icy surface and evidence of a vast ocean, following the amazing data from 11 flybys of the Galileo spacecraft over a decade ago and recent Hubble observations suggesting plumes of water shooting out from the moon,” says Grunsfeld.

“We’re excited about the potential of this new mission and these instruments to unravel the mysteries of Europa in our quest to find evidence of life beyond Earth.”

Planetary scientists have long desired a speedy return on Europa, ever since the groundbreaking discoveries of NASA’s Galileo Jupiter orbiter in the 1990s showed that the alien world possessed a substantial and deep subsurface ocean beneath an icy shell that appears to interact with and alter the surface in recent times.

NASA’s Europa mission would blastoff perhaps as soon as 2022, depending on the budget allocation and rocket selection, whose candidates include the heavy lift Space Launch System (SLS).

The solar powered probe will go into orbit around Jupiter for a three year mission.

“The mission concept is that it will conduct multiple flyby’s of Europa,” said Jim Green. director, Planetary Science Division, NASA Headquarters, during the briefing.

“The purpose is to determine if Europa is a habitable place. It shows few craters, a brown gum on the surface and cracks where the subsurface meet the surface. There may be organics and nutrients among the discoloration at the surface.”

Europa is at or near the top of the list for most likely places in our solar system that could support life. Mars is also near the top of the list and currently being explored by a fleet of NASA robotic probes including surface rovers Curiosity and Opportunity.

“Europa is one of those critical areas where we believe that the environment is just perfect for potential development of life,” said Green. “This mission will be that step that helps us understand that environment and hopefully give us an indication of how habitable the environment could be.”

The exact thickness of Europa’s ice shell and extent of its subsurface ocean is not known.

The ice shell thickness has been inferred by some scientists to be perhaps only 5 to 10 kilometers thick based on data from Galileo, the Hubble Space Telescope, a Cassini flyby and other ground and space based observations.

The global ocean might be twice the volume of all of Earth’s water. Research indicates that it is salty, may possess organics, and has a rocky sea floor. Tidal heating from Jupiter could provide the energy for mixing and chemical reactions, supplemented by undersea volcanoes spewing heat and minerals to support living creatures, if they exist.

“Europa could be the best place in the solar system to look for present day life beyond our home planet,” says NASA officials.

The instruments chosen today by NASA will help answer the question of habitability, but they are not life detection instruments in and of themselves. That would require a follow on mission.

“They could find indications of life, but they’re not life detectors,” said Curt Niebur, Europa program scientist at NASA Headquarters in Washington. “We currently don’t even have consensus in the scientific community as to what we would measure that would tell everybody with confidence this thing you’re looking at is alive. Building a life detector is incredibly difficult.”

‘During the three year mission, the orbiter will conduct 45 close flyby’s of Europa,” Niebur told Universe Today. “These will occur about every two to three weeks.”

The close flyby’s will vary in altitude from 16 miles to 1,700 miles (25 kilometers to 2,700 kilometers).

“The mass spectrometer has a range of 1 to 2000 daltons, Niebur told me. “That’s a much wider range than Cassini. However there will be no means aboard to determine chirality.” The presence of Chiral compounds could be an indicator of life.

Right now the Europa mission is in the formulation stage with a budget of about $10 million this year and $30 Million in 2016. Over the next three years the mission concept will be defined.

The mission is expected to cost in the range of at least $2 Billion or more.

Here’s a NASA description of the 9 instruments selected:

Plasma Instrument for Magnetic Sounding (PIMS) — principal investigator Dr. Joseph Westlake of Johns Hopkins Applied Physics Laboratory (APL), Laurel, Maryland. This instrument works in conjunction with a magnetometer and is key to determining Europa’s ice shell thickness, ocean depth, and salinity by correcting the magnetic induction signal for plasma currents around Europa.

Interior Characterization of Europa using Magnetometry (ICEMAG) — principal investigator Dr. Carol Raymond of NASA’s Jet Propulsion Laboratory (JPL), Pasadena, California. This magnetometer will measure the magnetic field near Europa and – in conjunction with the PIMS instrument – infer the location, thickness and salinity of Europa’s subsurface ocean using multi-frequency electromagnetic sounding.

Mapping Imaging Spectrometer for Europa (MISE) — principal investigator Dr. Diana Blaney of JPL. This instrument will probe the composition of Europa, identifying and mapping the distributions of organics, salts, acid hydrates, water ice phases, and other materials to determine the habitability of Europa’s ocean.

Europa Imaging System (EIS) — principal investigator Dr. Elizabeth Turtle of APL. The wide and narrow angle cameras on this instrument will map most of Europa at 50 meter (164 foot) resolution, and will provide images of areas of Europa’s surface at up to 100 times higher resolution.

Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) — principal investigator Dr. Donald Blankenship of the University of Texas, Austin. This dual-frequency ice penetrating radar instrument is designed to characterize and sound Europa’s icy crust from the near-surface to the ocean, revealing the hidden structure of Europa’s ice shell and potential water within.

Europa Thermal Emission Imaging System (E-THEMIS) — principal investigator Dr. Philip Christensen of Arizona State University, Tempe. This “heat detector” will provide high spatial resolution, multi-spectral thermal imaging of Europa to help detect active sites, such as potential vents erupting plumes of water into space.

MAss SPectrometer for Planetary EXploration/Europa (MASPEX) — principal investigator Dr. Jack (Hunter) Waite of the Southwest Research Institute (SwRI), San Antonio. This instrument will determine the composition of the surface and subsurface ocean by measuring Europa’s extremely tenuous atmosphere and any surface material ejected into space.

Ultraviolet Spectrograph/Europa (UVS) — principal investigator Dr. Kurt Retherford of SwRI. This instrument will adopt the same technique used by the Hubble Space Telescope to detect the likely presence of water plumes erupting from Europa’s surface. UVS will be able to detect small plumes and will provide valuable data about the composition and dynamics of the moon’s rarefied atmosphere.

SUrface Dust Mass Analyzer (SUDA) — principal investigator Dr. Sascha Kempf of the University of Colorado, Boulder. This instrument will measure the composition of small, solid particles ejected from Europa, providing the opportunity to directly sample the surface and potential plumes on low-altitude flybys.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

January 5, 2015December 23, 2015 by Paul Patton

Defining Life I: What are Astrobiologists Looking For?

In December, 2014 researchers in the Mars Science Laboratory Project announced that they had made the first definitive detection of organic materials on the surface of Mars. The sample was taken on May 19, 2013 from a rock that mission controllers named “Cumberland”. The Curiosity Mars rover drilled a hole 1.6 cm wide and 6.6 cm deep in the Martian rock. Powered rock from the hole was delivered to the rover’s Sample Analysis at Mars (SAM) instrument for analysis. The scientists drew their conclusions only after months of careful analysis. The identity and complexity of the organic substances remains uncertain, because they may have been altered by perchlorates that were also present in the rock, when the material was heated for analysis. The Viking Mars landers of 1976 had earlier failed to detect organic materials on Mars. Credits: NASA/Jet Propulsion Laboratory, Caltech

How can astrobiologists find extraterrestrial life? In everyday life, we usually don’t have any problem telling that a dog or a rosebush is a living thing and a rock isn’t. In the climatic scene of the movie ‘Europa Report’ we can tell at a glance that the multi-tentacled creature discovered swimming in the ocean of Jupiter’s moon Europa is alive, complicated, and quite possibly intelligent.

But unless something swims, walks, crawls, or slithers past the cameras of a watching spacecraft, astrobiologists face a much tougher job. They need to devise tests that will allow them to infer the presence of alien microbial life from spacecraft data. They need to be able to recognize fossil traces of past alien life. They need to be able to determine whether the atmospheres of distant planets circling other stars contain the tell-tale traces of unfamiliar forms of life. They need ways to infer the presence of life from knowledge of its properties. A definition of life would tell them what those properties are, and how to look for them. This is the first of a two part series exploring how our concept of life influences the search for extraterrestrial life.

What is it that sets living things apart? For centuries, philosophers and scientists have sought an answer. The philosopher Aristotle (384-322 BC) devoted a great deal of effort to dissecting animals and studying living things. He supposed that they had distinctive special capacities that set them apart from things that aren’t alive. Inspired by the mechanical inventions of his times, the Renaissance philosopher Rene Descartes (1596-1650) believed that living things were like clockwork machines, their special capacities deriving from the way their parts were organized.

In 1944, the physicist Erwin Schrödinger (1887-1961) wrote What is Life? In it, he proposed that the fundamental phenomena of life, including even how parents pass on their traits to their offspring, could be understood by studying the physics and chemistry of living things. Schrödinger’s book was an inspiration to the science of molecular biology.

Living organisms are made of large complicated molecules with backbones of linked carbon atoms. Molecular biologists were able to explain many of the functions of life in terms of these organic molecules and the chemical reactions they undergo when dissolved in liquid water. In 1955 James Watson and Francis Crick discovered the structure of deoxyribonucleic acid (DNA) and showed how it could be the storehouse of hereditary information passed from parent to offspring.

While all this research and theorizing has vastly increased our understanding of life, it hasn’t produced a satisfactory definition of life; a definition that would allow us to reliably distinguish things that are alive from things that aren’t. In 2012 the philosopher Edouard Mahery argued that coming up with a single definition of life was both impossible and pointless. Astrobiologists get by as best they can with definitions that are partial, and that have exceptions. Their search is conditioned by our knowledge of the specific features of life on Earth; the only life we currently know.

Here on Earth, living things are distinctive in their chemical composition. Besides carbon, the elements hydrogen, nitrogen, oxygen, phosphorus, and sulfur are particularly important to the large organic molecules that make up terrestrial life. Water is a necessary solvent. Since we don’t know for sure what else might be possible, the search for extraterrestrial life typically assumes its chemical composition will be similar to that of life on Earth.

Making use of that assumption, astrobiologists assign a high priority to the search for water on other celestial bodies. Spacecraft evidence has proven that Mars once had bodies of liquid water on its surface. Determining the history and extent of this water is a central goal of Mars exploration. Astrobiologists are excited by evidence of subsurface oceans of water on Jupiter’s moon Europa, Saturn’s moon Enceladus, and perhaps on other moons or dwarf planets. But while the presence of liquid water implies conditions appropriate for Earth-like life, it doesn’t prove that such life exists or has ever existed.

Jupiter’s icy moon Europa appears to host liquid water, an essential condition for life as we know it on Earth. Its surface is covered with a crust of water ice. The Voyager and Galileo spacecraft have provided evidence that under this icy crust, there is an ocean of saltwater, containing more liquid water than all the oceans of Earth. Europa’s interior is heated by gravitational tidal forces exerted by giant Jupiter. This heat energy may drive volcanism, hydrothermal vents, and the production of chemical energy sources that living things could make use of. Interaction between materials from Europa’s surface and the ocean environment beneath could make available carbon and other chemical elements essential for Earth-like life.
Credits: NASA/Jet Propulsion Laboratory, SETI Institute

Organic chemicals are necessary for Earth-like life, but, as for water, their presence doesn’t prove that life exists, because organic materials can also be formed by non-biological processes. In 1976, NASA’s two Viking landers were the first spacecraft to make fully successful landings on Mars. They carried an instrument; called the gas chromatograph-mass spectrometer, that tested the soil for organic molecules.

Even without life, scientists expected to find some organic materials in the Martian soil. Organic materials formed by non-biological processes are found in carbonaceous meteorites, and some of these meteorites should have fallen on Mars. They were surprised to find nothing at all. At the time, the failure to find organic molecules was considered a major blow to the possibility of life on Mars.

In 2008, NASA’s Phoenix lander discovered an explanation of why Viking didn’t detect organic molecules. If found that the Martian soil contains perchlorates. Containing oxygen and chlorine, perchlorates are oxidizing agents that can break down organic material. While perchlorates and organic molecules could coexist in Martian soil, scientists determined that heating the soil for the Viking analysis would have caused the perchlorates to destroy any organic material it contained. Martian soil might contain organic materials, after all.

At a news briefing in December 2014, NASA announced that an instrument carried on board the Curiosity Mars rover had succeeded in detected simple organic molecules on Mars for the first time. Researchers believe it is possible that the molecules detected may be breakdown products of more complex organic molecules that were broken down by perchlorates during the process of analysis.

electron micrograph of Mars meteorite — In 1996 a team of scientists lead by Dr. David McKay of NASA’s Johnson Space Center announced possible evidence of life on Mars. The evidence came from their studies of a Martian meteorite found in Antarctica, called Alan Hills 84001. The researchers found chemical and physical traces of possible life including carbonate globules that resemble terrestrial nanobacteria (electron micrograph shown) and polycyclic aromatic hydrocarbons. In terrestrial rock, the chemical traces would be considered breakdown products of bacterial life. The findings became the subject of controversy as non-biological explanations for the findings were found. Today, they are no longer regarded as definitive evidence of Martian life.
Credits: NASA Johnson Space Center

The chemical make-up of terrestrial life has also guided the search for traces of life in Martian meteorites. In 1996 a team of investigators lead by David McKay of the Johnson Space Center in Houston reported evidence that a Martian meteorite found at Alan Hills in Antarctica in 1984 contained chemical and physical evidence of past Martian life.

There have since been similar claims about other Martian meteorites. But, non-biological explanations for many of the findings have been proposed, and the whole subject has remained embroiled in controversy. Meteorites have not so far yielded the kind of evidence needed to prove the existence of extraterrestrial life beyond reasonable doubt.

Following Aristotle, most scientists prefer to define life in terms of its capacities rather than its composition. In the second installment, we will explore how our understanding of life’s capacities has influenced the search for extraterrestrial life.

References and further reading:

N. Atkinson (2009) Perchlorates and Water Make for Potential Habitable Environment on Mars, Universe Today.

S. A. Benner (2010), Defining life, Astrobiology, 10(10):1021-1030.

E. Machery (2012), Why I stopped worrying about the definition of life…and why you should as well, Synthese, 185:145-164.

L. J. Mix (2015), Defending definitions of life, Astrobiology, 15(1) posted on-line in advance of publication.

T. Reyes (2014) NASA’s Curiosity Rover detects Methane, Organics on Mars, Universe Today.

S. Tirard, M. Morange, and A. Lazcano, (2010), The definition of life: A brief history of an elusive scientific endeavor, Astrobiology, 10(10):1003-1009.

Did Viking Mars landers find life’s building blocks? Missing piece inspires new look at puzzle. Science Daily Featured Research Sept. 5, 2010

NASA rover finds active and ancient organic chemistry on Mars, Jet Propulsion laboratory, California Institute of Technology, News, Dec. 16, 2014.

Europa: Ingredients for Life?, National Aeronautics and Space Administration.